CVE-2021-20035
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedImproper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA command injection vulnerability in the SMA100 series security appliance management interface allows an authenticated remote attacker to inject and execute arbitrary shell commands. The injected commands execute with 'nobody' user privileges, which limits direct root access but can still be leveraged for denial of service or further privilege escalation attempts.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 9.0.0.11-31sv>= 10.2.0.0, < 10.2.0.8-37sv>= 10.2.1.0, < 10.2.1.1-19sv< 9.0.0.11-31sv>= 10.2.0.0, < 10.2.0.8-37sv>= 10.2.1.0, < 10.2.1.1-19sv< 9.0.0.11-31sv>= 10.2.0.0, < 10.2.0.8-37sv>= 10.2.1.0, < 10.2.1.1-19sv< 9.0.0.11-31sv>= 10.2.0.0, < 10.2.0.8-37sv>= 10.2.1.0, < 10.2.1.1-19sv< 9.0.0.11-31sv>= 10.2.0.0, < 10.2.0.8-37sv>= 10.2.1.0, < 10.2.1.1-19svCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the SMA100 modelAccess the device web interface and locate the model number in the dashboard or system information page, or run 'show system info' via CLIAffected if The model is not one of SMA 200, 210, 400, 410, or 500v
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Determine the installed firmware versionIn the web interface, go to Device > Settings > Firmware or check the main dashboard for the firmware version number; alternatively, run 'version' or 'show system info' via CLIAffected if The firmware version cannot be determined or is not visible
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Compare firmware version against affected rangesMatch your installed firmware version to the affected ranges: < 9.0.0.11-31sv, >= 10.2.0.0 < 10.2.0.8-37sv, or >= 10.2.1.0 < 10.2.1.1-19svAffected if The installed version falls within any of the three vulnerable ranges
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Verify management interface accessibilityConfirm the SMA web management interface (HTTPS on port 443 or custom port) is reachable from network locations where attackers could authenticateAffected if The management interface is exposed to untrusted networks without proper access controls
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Check for existing administrator sessionsReview active administrative sessions or recent authentication logs in the web interface under Logs > Admin Sessions or similarAffected if Multiple or unexpected administrator accounts exist, indicating broader attack surface
The environment is affected if the device is an SMA 200/210/400/410/500v running a firmware version within the vulnerable ranges and the management interface is accessible to potential attackers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped9.0.0.11-31sv10.2.0.8-37sv10.2.1.1-19sv
Apply the vendor patch when available. In the interim, restrict management interface access to trusted IP addresses only and ensure strong authentication controls are in place to prevent unauthorized users from reaching the vulnerable interface.
Upgrade to firmware 9.0.0.11-31sv (for 9.x branches), 10.2.0.8-37sv (for 10.2.0.x branch), or 10.2.1.1-19sv (for 10.2.1.x branch) or later respective releases
- Identify the current firmware version of the SMA 100 appliance (SMA 200, 210, 400, 410, or 500v) by accessing the management interface
- Determine which version branch is currently in use (9.x.x.x or 10.2.x.x)
- For devices running firmware < 9.0.0.11-31sv: Upgrade to firmware version 9.0.0.11-31sv or later
- For devices running firmware >= 10.2.0.0 and < 10.2.0.8-37sv: Upgrade to firmware version 10.2.0.8-37sv or later
- For devices running firmware >= 10.2.1.0 and < 10.2.1.1-19sv: Upgrade to firmware version 10.2.1.1-19sv or later
- Download the appropriate firmware from the official SonicWall support portal (psirt.global.sonicwall.com)
- Upload and apply the new firmware through the SMA management interface
- Verify the upgrade was successful and the device is functioning normally
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation12.0 h
- Testing10.0 h
- Review / QA6.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20035 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-20035 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data